High speed direct-binary to binary-coded-decimal converter and scaler

Telemetry (pulse code modulated) digital system usually sends binary numbers representing some parameter that is not value of binary number. Received binary number must be scaled and converted to binary coded decimal to operate readout device to display true value. Group of adders speed up binary number conversion and scaling in one operation

Inferring land use from mobile phone activity

Understanding the spatiotemporal distribution of people within a city is crucial to many planning applications. Obtaining data to create required knowledge, currently involves costly survey methods. At the same time ubiquitous mobile sensors from personal GPS devices to mobile phones are collecting massive amounts of data on urban systems. The locations, communications, and activities of millions of people are recorded and stored by new information technologies. This work utilizes novel dynamic data, generated by mobile phone users, to measure spatiotemporal changes in population. In the process, we identify the relationship between land use and dynamic population over the course of a typical week. A machine learning classification algorithm is used to identify clusters of locations with similar zoned uses and mobile phone activity patterns. It is shown that the mobile phone data is capable of delivering useful information on actual land use that supplements zoning regulations.Comment: To be presented at ACM UrbComp201

Telephone multiline signaling using common signal pair

An operator can rapidly and automatically produce coded electrical signals by manipulating mechanical thumb wheel switches so as to instruct a service center to connect any number of telephone lines to the console thus enabling the operator to listen and/or talk over several lines simultaneously. The system includes an on-site console having several mechanically operated thumb wheel switches to which the desired lines to be connected can be dialed in. Electrical coded signals are fed to a number of banks of line AND gates representing units, tens and hundreds, a group of channel gates, and a command gate. These signals are gated out in a controlled manner to an encoder which generates tones that are transmitted over a single line to a communication service center

Coupling Human Mobility and Social Ties

Studies using massive, passively data collected from communication technologies have revealed many ubiquitous aspects of social networks, helping us understand and model social media, information diffusion, and organizational dynamics. More recently, these data have come tagged with geographic information, enabling studies of human mobility patterns and the science of cities. We combine these two pursuits and uncover reproducible mobility patterns amongst social contacts. First, we introduce measures of mobility similarity and predictability and measure them for populations of users in three large urban areas. We find individuals' visitations patterns are far more similar to and predictable by social contacts than strangers and that these measures are positively correlated with tie strength. Unsupervised clustering of hourly variations in mobility similarity identifies three categories of social ties and suggests geography is an important feature to contextualize social relationships. We find that the composition of a user's ego network in terms of the type of contacts they keep is correlated with mobility behavior. Finally, we extend a popular mobility model to include movement choices based on social contacts and compare it's ability to reproduce empirical measurements with two additional models of mobility

Impact of a mass vaccination campaign against a meningitis epidemic in a refugee camp.

Serogroup A meningococcus epidemics occurred in refugee populations in Zaire in August 1994. The paper analyses the public health impact of a mass vaccination campaign implemented in a large refugee camp. We compared meningitis incidence rates from 2 similar camps. In Kibumba camp, vaccination was implemented early in the course of the epidemic whilst in the control camp (Katale), vaccination was delayed. At a threshold of 15 cases per 100 000 population per week an immunization campaign was implemented. Attack rates were 94 and 134 per 100,000 in Kibumba and Katale respectively over 2 months. In Kibumba, one week after crossing the threshold, 121,588 doses of vaccine were administered covering 76% of all refugees. Vaccination may have prevented 68 cases (30% of the expected cases). Despite its rapid institution and the high coverage achieved, the vaccination campaign had a limited impact on morbidity due to meningitis. In the early phase in refugee camps, the relative priorities of meningitis vaccination and case management need to be better defined

Paper Session I-A - Neutral Particle Beam Overview

The goal of the Neutral Particle Beam (NPB) technology program is to develop a multimission directed energy weapon (DEW) system which can function as an effective component in a Strategic Defense System. The NPB has the capability to be used as both a weapon and discriminator platform. It can kill missiles and reentry vehicles in the boost, post-boost, and mid-course portion of an ICBM trajectory as well as discriminated objects during the midcourse phase. Objects from those boosters and buses not engaged in the boost and post boost phase would be engaged once the reentry vehicles and decoys have been deployed, i.e. during the midcourse phase of the trajectory. The NPB can be used to provide a passive, active, and interactive discrimination capability against these targets. Passive discrimination is accomplished by viewing visible, ultraviolet (UV) and/or infrared (IR) emissions from targets and decoys using on-board acquisition sensors. Active discrimination is accomplished by illuminating targets and decoys with a laser tracker on-board the NPB; while Interactive discrimination is accomplished by illuminating the target with the NPB which results in the emission of X-rays and neutrons which are proportional to the mass of the target. These emitted particles are measured by a free flying detector to determine the mass of the objects. During the discrimination process target state vectors (position and velocity) can be determined which can be handed over to space-based or ground-based interceptors. All the sensors are on the same platform. This reduces data processing since sensor-to-sensor correlation is not required

A light-driven, one-dimensional dimethylsulfide biogeochemical cycling model for the Sargasso Sea

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): G02009, doi:10.1029/2007JG000426.We evaluate the extent to which dimethylsulfide (DMS) cycling in an open-ocean environment can be constrained and parameterized utilizing emerging evidence for the significant impacts of solar ultraviolet radiation (UVR) on the marine organic sulfur cycle. Using the Dacey et al. (1998) 1992–1994 Sargasso Sea DMS data set, in conjunction with an offline turbulent mixing model, we develop and optimize a light driven, one-dimensional DMS model for the upper 140 m. The DMS numerical model is primarily diagnostic in that it incorporates observations of bacterial, phytoplankton, physical, and optical quantities concurrently measured as part of the Bermuda Atlantic Time-series Study (BATS) and Bermuda Bio-Optical Project (BBOP) programs. With the exception of sea-to-air ventilation, each of the sulfur cycling terms is explicitly parameterized or altered by the radiation field. Overall, the model shows considerable skill in capturing the salient features of the DMS distribution, specifically the observed DMS summer paradox whereby peak summer DMS concentrations occur coincident with annual minima in phytoplankton pigment biomass and primary production. The dominant processes controlling the upper-ocean DMS concentrations are phytoplankton UVR-induced DMS release superimposed upon more surface oriented processes such as photolysis and sea-to-air ventilation. The results also demonstrate that mixing alone is not enough to parameterize DMS distributions in this environment. It is critical to directly parameterize the seasonal changes in the flux and attenuation of solar radiation in the upper water column to describe the DMS distribution with depth and allow for experimentation under a variety of climate change scenarios.This work was supported by NASA under an Earth System Science Fellowship, a WHOI Ocean and Climate Change Institute Postdoctoral scholarship, and NSF OCE-0525928

Sensor corrections for Sea-Bird SBE-41CP and SBE-41 CTDs

Author Posting. © American Meteorological Society, 2007. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Atmospheric and Oceanic Technology 24 (2007): 1117-1130, doi:10.1175/JTECH2016.1.Sensor response corrections for two models of Sea-Bird Electronics, Inc., conductivity–temperature–depth (CTD) instruments (the SBE-41CP and SBE-41) designed for low-energy profiling applications were estimated and applied to oceanographic data. Three SBE-41CP CTDs mounted on prototype ice-tethered profilers deployed in the Arctic Ocean sampled diffusive thermohaline staircases and telemetered data to shore at their full 1-Hz resolution. Estimations of and corrections for finite thermistor time response, time shifts between when a parcel of water was sampled by the thermistor and when it was sampled by the conductivity cell, and the errors in salinity induced by the thermal inertia of the conductivity cell are developed with these data. In addition, thousands of profiles from Argo profiling floats equipped with SBE-41 CTDs were screened to select examples where thermally well-mixed surface layers overlaid strong thermoclines for which standard processing often yields spuriously fresh salinity estimates. Hundreds of profiles so identified are used to estimate and correct for the conductivity cell thermal mass error in SBE-41 CTDs.The National Ocean Partnership Program and the National Oceanic and Atmospheric Administration (NOAA) Office of Oceanic and Atmospheric Research funded this analysis. The ITP data were acquired under National Science Foundation (NSF) Grant OCE0324233

How variable is mixing efficiency in the abyss?

Author Posting. © American Geophysical Union, 2020. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 47 (2020): e2019GL086813, doi: 10.1029/2019GL086813.Mixing efficiency is an important turbulent flow property in fluid dynamics, whose variability potentially affects the large‐scale ocean circulation. However, there are several confusing definitions. Here we compare and contrast patch‐wise versus bulk estimates of mixing efficiency in the abyss by revisiting data from previous extensive field surveys in the Brazil Basin. Observed patch‐wise efficiency is highly variable over a wide range of turbulence intensity. Bulk efficiency is dominated by rare extreme turbulence events. In the case where enhanced near‐bottom turbulence is thought to be driven by breaking of small‐scale internal tides, the estimated bulk efficiency is 20%, close to the conventional value of 17%. On the other hand, where enhanced near‐bottom turbulence appears to be convectively driven by hydraulic overflows, bulk efficiency is suggested to be as large as 45%, which has implications for a further significant role of overflow mixing on deep‐water mass transformation.TI is a JSPS Overseas Research Fellow. LS, KLP, and JMT acknowledge support from the U.S. National Science Foundation and Office of Naval Research. The authors express their gratitude to Ali Mashayek and an anonymous reviewer for their useful comments on the original manuscript. Data used in this study is available from the Woods Hole Open Access Server (https://hdl.handle.net/1912/25456).2020-09-2

A double-diffusive interface tank for dynamic-response studies

Author Posting. © Sears Foundation for Marine Research, 2005. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 63 (2005): 263-289, doi:10.1357/0022240053693842.A large tank capable of long-term maintenance of a sharp temperature-salinity interface has been developed and applied to measurements of the dynamical response of oceanographic sensors. A two-layer salt-stratified system is heated from below and cooled from above to provide two convectively mixed layers with a thin double-diffusive interface separating them. A temperature jump exceeding 10°C can be maintained over 1–2 cm (a vertical temperature gradient of order 103°C/m) for several weeks. A variable speed-lowering system allows testing of the dynamic response of conductivity and temperature sensors in full-size oceanographic instruments. An acoustic echo sounder and shadowgraph system provide nondisruptive monitoring of the interface and layer microstructure. Tests of several sensor systems show how data from the facility is used to determine sensor response times using several fitting techniques and the speed dependence of thermometer time constants is illustrated. The linearity of the conductivity–temperature relationship across the interface is proposed as a figure of merit for design of lag-correction filters to accurately match temperature and conductivity sensors for the computation of salinity. The effects of finite interface thickness, slow sensor sampling rates and the thermal mass of the conductivity cell are treated. Sensor response characterization is especially important for autonomous instruments where data processing and compression must be performed in-situ, but is also helpful in the development of new sensors and in assuring accurate salinity records from traditional wire-lowered and towed systems.This research was supported by the National Science Foundation, grants OCE-97-11869 and OCE-02-40956, NOAA CORC grant 154368 and a WHOI Mellon Technical Staff Award